The present invention relates to a novel liquid detergent composition and, in particular, to an improved liquid detergent composition having excellent detergency and foaming power as well as a markedly reduced tendency toward film formation on the surface.
As is well known, various kinds of anionic surface active agents have been used hitherto as a main ingredient of liquid detergent compositions, among which magnesium .alpha.-olefinsulfonates is known to have excellent detergency and foaming power in comparison with other anionic surface active agents such as alkali metal salts or alkaline earth metal salts of linear alkylbenzenesulfonic acids and alkylethoxysulfuric acids.
One of the major problems in liquid detergent compositions containing a magnesium .alpha.-olefinsulfonate is, however, a tendency toward film formation on the surface of the liquid composition when exposed to open air, especially, when the total content of the surface active agents as the main ingredients is in the range of from 10 to 70% by weight and the content of the magnesium .alpha.-olefinsulfonate exceeds 5% by weight. In practical use of the liquid detergent compositions, such film formation often takes place, for example, when the liquid composition is left standing in a measuring cup or when the cap of the container is left removed and fresh air is allowed to contact with the liquid surface, and naturally causes some inconvenience in the subsequent use of the detergent composition. Moreover, the phenomenon of film formation on the surface presents a difficult problem in quality control in the manufacturing process.
In order to mitigate the above described problem of film formation on the surface, improved liquid detergent compositions containing a magnesium .alpha.-olefinsulfonate have been proposed, for example, in Japanese Pat. Nos. SHO 52-8009 and SHO 52-30807, according to which the magnesium .alpha.-olefinsulfonate is combined with certain kinds of nonionic surface active agents.
These liquid detergent compositions face, however, another problem in that, in addition to the undesirably high content of the nonionic surface active agents required for reducing the film-forming tendency, the desired performance characteristics of a detergent composition such as detergency or foaming power are inevitably degraded even though surface film formation itself is effectively prevented.